Display device

ABSTRACT

A display device includes a first electrode, a pixel define layer disposed on the first electrode, the pixel define layer including an opening, an organic emission layer disposed on the pixel define layer, the organic emission layer in electrical communication with the first electrode through the opening, a second electrode disposed on the organic emission layer, a light recycle layer disposed on the second electrode, and a color filter layer disposed on the light recycle layer, the color filter layer including a quantum dot, wherein a width of the organic emission layer is longer than a width of the color filter layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2019-0009438 filed in the Korean IntellectualProperty Office on Jan. 24, 2019, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND 1. Field

A display device capable of displaying an image is disclosed.

2. Description of the Related Art

Display devices include, for example, liquid crystal displays (“LCDs”),a plasma display panels (“PDPs”), and an organic light emitting diode(“OLED”) displays. Liquid crystal displays (“LCDs”) and organic lightemitting diode (“OLED”) displays may be made in the form of a thin film,may exhibit, for example, low power and low exothermicity, and may beapplied to, e.g., used in, various display devices such as mobiledevices, computer monitors, and televisions (“TVs”).

An organic light emitting diode (“OLED”) display may be very thin andflexible compared with other display devices, and may be applied to,e.g., used in, flexible display devices such as a rollable, stretchable,or foldable device or a small portable electronic device such as, forexample, a smart band or a smart watch.

It would be desirable to dispose, e.g., include, a color filterincluding quantum dots in order to improve color purity of an organiclight emitting diode (“OLED”) display. A quantum dot is a nanocrystalsemiconductor material having a diameter of less than or equal to around10 nanometers (nm), which shows, e.g., exhibits, quantum confinementeffects. Quantum dots generate stronger light in a narrow wavelengthregion than phosphors, and thus are effective in improvement of colorpurity of emitted light.

Quantum dots emit light while excited electrons are transitioned from aconduction band to a valance band and wavelengths are changed dependingupon a particle size even in the same material. As smaller quantum dotsemit light of a shorter wavelength, light in a desirable wavelengthregion may be obtained by adjusting the sizes of the quantum dots.

SUMMARY

A display device having improved photo-efficiency and color purity isprovided.

According to an embodiment, a display device includes a first electrode,a pixel define layer disposed on the first electrode, the pixel definelayer include an opening, an organic emission layer disposed on thepixel define layer, the organic emission layer in electricalcommunication with the first electrode through the opening, a secondelectrode disposed on the organic emission layer, a light recycle layerdisposed on the second electrode, and a color filter layer disposed onthe light recycle layer, the color filter layer including a quantum dot,wherein a width of the organic emission layer is longer than a width ofthe color filter layer.

A side of the pixel define layer adjacent the opening may be slantedwith respect to an upper surface of the pixel define layer, and theorganic emission layer may be extend from the first electrode to aportion of the upper surface of the pixel define layer adjacent theslanted side of the pixel define layer.

A width of the opening may be longer than or equal to a width of thecolor filter layer.

At least one portion of the color filter layer may be disposed in theopening.

The organic emission layer may emit a third light, and the light recyclelayer may transmit the third light and may reflect a first light and asecond light, each of which has a different wavelength than the thirdlight.

The first light may be red light, the second light may be green light,and the third light may be blue light.

The light recycle layer may have a transmittance for the third light ofabout 90% to about 100%.

The light recycle layer may have a transmittance for each of the firstlight and the second light of about 0% to about 20%.

The light recycle layer may have a thickness of about 0.5 micrometers(μm) to about 5 μm.

The color filter layer may include a first color filter layer includinga first quantum dot configured to convert the third light into the firstlight, and a second color filter layer including a second quantum dotconfigured to convert the third light into the second light.

The display device may further include a substrate, the first electrodebeing disposed on an upper surface of the substrate; and a transmissivelayer adjacent to the first color filter layer, the second color filterlayer, or a combination thereof in a direction parallel to the uppersurface of the substrate.

The transmissive layer and/or the color filter layer may include a lightscatterer.

The display device may further include a light blocking member betweeneach of the first color filter layer, the second color filter layer, andthe transmissive layer in the direction parallel to the upper surface ofthe substrate.

The light recycle layer may be overlapped with the first color filterlayer, the second color filter layer, or a combination thereof.

The second electrode and the light recycle layer may be in directcontact with each other, and at least one portion of an upper surface ofthe second electrode may include an undulating structure.

The second electrode and the light recycle layer may be in directcontact, at least one portion of an upper surface of the light recyclelayer comprises an undulating structure, and at least one portion of alower surface of the light recycle layer may include an undulatingstructure.

The display device may further include a third light blocking layerdisposed on the color filter layer and overlapped with the first colorfilter layer, the second color filter layer, or a combination thereof.

The quantum dot may include a Group II-VI compound that does not includeCd, a Group III-V compound, a Group IV-VI compound, a Group IV elementor compound, a Group compound, a Group I-II-IV-VI compound that does notinclude Cd, or a combination thereof.

The quantum dot may have a core-shell structure.

A display device with improved photo-efficiency and color purity may beprovided.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other advantages and features of this disclosure willbecome more apparent by describing in further detail exemplaryembodiments thereof with reference to the accompanying drawings, inwhich:

FIG. 1 is a cross-sectional view of an embodiment showing a displaydevice,

FIG. 2 is a schematic diagram of an embodiment schematicallyillustrating a light conversion process of a color filter layer in onepixel of a display device,

FIG. 3 is a schematic diagram schematically illustrating a lightconversion process of a color filter layer,

FIG. 4 is a graph of intensity (arbitrary units (a.u)) versus wavelength(nanometers (nm)) showing light transmittance changes of the lightrecycle layer depending on a wavelength according to viewing anglechanges,

FIGS. 5 to 8 are cross-sectional views of embodiments in which aconcavo-convex, e.g., undulating, structure is applied to, e.g., usedfor, a second electrode, a light recycle layer, or a combination thereofof the display device, and

FIG. 9 is a cross-sectional view of an embodiment showing a displaydevice further including a third light blocking layer.

DETAILED DESCRIPTION

Hereinafter, example embodiments of the present invention will bedescribed in detail so that a person skilled in the art would understandthe same. This disclosure may, however, be embodied in many differentforms and is not construed as limited to the example embodiments setforth herein.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it can be directly on the other element orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” another element, there are nointervening elements present.

It will be understood that, although the terms “first,” “second,”“third” etc. may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, “a first element,” “component,” “region,” “layer” or“section” discussed below could be termed a second element, component,region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein,“a”, “an,” “the,” and “at least one” do not denote a limitation ofquantity, and are intended to include both the singular and plural,unless the context clearly indicates otherwise. For example, “anelement” has the same meaning as “at least one element,” unless thecontext clearly indicates otherwise. “At least one” is not to beconstrued as limiting “a” or “an.” “Or” means “and/or.” As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items. It will be further understood that theterms “comprises” and/or “comprising,” or “includes” and/or “including”when used in this specification, specify the presence of statedfeatures, regions, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, regions, integers, steps, operations, elements,components, and/or groups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother element as illustrated in the Figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the Figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on “upper” sides of the other elements. The exemplary term“lower,” can therefore, encompasses both an orientation of “lower” and“upper,” depending on the particular orientation of the figure.Similarly, if the device in one of the figures is turned over, elementsdescribed as “below” or “beneath” other elements would then be oriented“above” the other elements. The exemplary terms “below” or “beneath”can, therefore, encompass both an orientation of above and below.

“About” as used herein is inclusive of the stated value and means withinan acceptable range of deviation for the particular value as determinedby one of ordinary skill in the art, considering the measurement inquestion and the error associated with measurement of the particularquantity (i.e., the limitations of the measurement system). For example,“about” can mean within one or more standard deviations, or within ±30%,20%, 10% or 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

As used herein, “Group” may refer to a group of Periodic Table.

As used herein, “Group I” may refer to Group IA and Group IB, andexamples may include Li, Na, K, Rb, and Cs, but are not limited thereto.

As used herein, “Group II” may refer to Group IIA and Group IIB, andexamples of Group II metal may be Cd, Zn, Hg, and Mg, but are notlimited thereto.

As used herein, examples of “Group II metal” may refer to a Group IImetal, for example Zn, Cd, Hg, or Mg.

As used herein, “Group III” may refer to Group IIIA and Group IIIB, andexamples of Group III metal may be Al, In, Ga, and TI, but are notlimited thereto.

As used herein, “Group IV” may refer to Group IVA and Group IVB, andexamples of a Group IV metal may be Si, Ge, and Sn, but are not limitedthereto. As used herein, the term “metal” may include a semi-metal suchas Si.

As used herein, “Group V” may refer to Group VA, and examples mayinclude nitrogen, phosphorus, arsenic, antimony, and bismuth, but arenot limited thereto.

As used herein, “Group VI” may refer to Group VIA, and examples mayinclude sulfur, selenium, and tellurium, but are not limited thereto.

Quantum dots may emit light in all directions, and it may be desirableto drive converted light through the quantum dots in a specificdirection or to increase energy for driving converted light, in order toimprove the photo-efficiency of a display device including the quantumdots. Therefore, even if a color filter including quantum dots isdisposed on an OLED display, a method of securing both photo-efficiencyand color purity is desirable.

FIG. 1 is a cross-sectional view showing a display device according toan embodiment.

Referring to FIG. 1, a display device 100 according to an embodiment hasa structure in which a first electrode 111, a pixel define layer 112, anorganic emission layer 113, a second electrode 114, a light recyclelayer 115, and a color filter layer 116 including quantum dots 16 whichare disposed in order on the structure substrate 110.

The substrate 110 may be a transparent insulating substrate and may bemade of a material having flexibility. The substrate 110 may includeglass or a polymer material in a film having a glass transitiontemperature (Tg) of greater than about 150° C. For example, thesubstrate may include a cycloolefin copolymer (“COC”) or a cycloolefinpolymer (“COP”) based material.

A driving circuit may be disposed directly on the substrate 110. Thedriving circuit may be connected to the organic emission layer 113 whichwill be described later. The driving circuit may include, for example, aline such as, for example, a scan line, a data line, a driving powersource line, a common power source line, or a combination thereof, atleast two thin film transistors (“TFTs”) connected to the wire andcorresponding to one organic light emitting diode, and a capacitor. Thedriving circuit may have a variety of structures. The first electrode111 may be disposed on the substrate 110, for example, directly on thedriving circuit. In an embodiment, the first electrode 111 may bedirectly connected to the driving circuit and may flow a current to theorganic emission layer 113, e.g., may provide a path of electricalcommunication to the organic emission layer 113.

In an embodiment, the first electrode 111 may include, for example,silver, aluminum, chromium, molybdenum, tungsten, titanium, gold,palladium, or an alloy thereof and a metal oxide such as molybdenumoxide, tungsten oxide, vanadium oxide, rhenium oxide, niobium oxide,tantalum oxide, titanium oxide, zinc oxide, nickel oxide, copper oxide,cobalt oxide, manganese oxide, chromium oxide, indium oxide, or acombination thereof. The first electrode 111 may have a monolayerstructure or may have a multilayer structure of two or more layers.

The first electrode 111 may include a material having lighttransmittance for light in an infrared or ultraviolet (“UV”) wavelengthregion or a material having semi-permeable properties to selectivelytransmit only light in a specific wavelength region. The first electrode111 may also function as a reflecting electrode to reflect light in avisible light wavelength region.

The pixel define layer 112 is disposed on the first electrode 111. Thepixel define layer 112 may be formed of, for example, an organicmaterial or an inorganic material. For example, the pixel define layer112 may include a photoresist, organic material such as, for example, apolyacryl-based resin, a polyimide-based resin, or an acryl-based resin,or an inorganic material such as a silicon compound. As a non-limitingexample, the pixel define layer 112 may be formed using a photoresistincluding a black pigment. In this case, the pixel define layer 112 mayhave a light-blocking function.

The pixel define layer 112 may include nano-structured scatteringparticles dispersed therein. The scattering particles may includeinorganic particles or polymer particles. For example, inorganicparticles such as, for example, silica, TiO₂, or ZrO₂, or polymerparticles such as, for example, polystyrene or polymethylmethacrylate(“PMMA”) may be included.

In an embodiment, the pixel define layer 112 includes an opening 1112exposing a portion of the first electrode 111. The side of the pixeldefine layer 112 formed by the opening 1112 may have a slant structure,e.g., the side of the pixel define layer 112 adjacent the opening 1112may be slanted with respect to an upper surface of the pixel definelayer 112.

In an embodiment, the pixel define layer 112 may define a pixel area ofthe display device 100 through, e.g., in, the opening 1112. An areawhere the opening 1112 of the pixel defining layer 112 is disposed maybe a pixel area where light is emitted and an area where the opening1112 is not disposed may be a non-light emitting region in which lightis blocked by a light blocking member that will be described later.

In an embodiment, the pixel area of the display device 100 may include afirst pixel area PX1, a second pixel area PX2, and a third pixel areaPX3. Each of the first pixel area PX1, the second pixel area PX2, andthe third pixel area PX3 may emit light having different wavelengthregions. That is, the first pixel area PX1 may emit a first light, thesecond pixel area PX2 may emit a second light, and the third pixel areaPX3 may emit a third light, and the first light to third light may belight of different wavelength regions.

Each of the first light, the second light, and the third light may varydepending on types of light emitted from the organic emission layer 113,and types of the quantum dots 16 included in the color filter layer 116.The first light may be red light, the second light may be green light,and the third light may be blue light. In this case, the first light maybelong to a wavelength region, e.g., have a wavelength in a range, ofabout 620 nm to about 680 nm, the second light may belong to awavelength region, e.g., have a wavelength in a range, of about 510 nmto about 580 nm, and the third light may belong to a wavelength region,e.g., have a wavelength in a range, of about 380 nm to about 488 nm.

The first light to the third light may be various combinations of thered light, the green light, and the blue light, which may be whitelight, and may be for example magenta, yellow, and cyan colors,respectively.

In an embodiment, the organic emission layer 113 may causeelectroluminescence of an organic light emitting material and thus emitlight having a predetermined wavelength. The organic emission layer 113may be disposed on the pixel define layer 112 and may electricallycontact, e.g., be in electrical communication with, the first electrode111 through the aforementioned opening 1112.

The organic emission layer 113 includes a first organic emission layer113 a disposed in a region corresponding to a first pixel area PX1, asecond organic emission layer 113 b disposed in a region correspondingto a second pixel area PX2, and a third organic emission layer 113 cdisposed in a region corresponding to a third pixel area PX3. The firstto third organic emission layers 113 a, 113 b, and 113 c respectivelyemit light in the same wavelength region, e.g., having the samewavelength, or having different wavelength regions.

In an embodiment, each of the first to third organic emission layers 113a, 113 b, and 113 c may emit a third light. When the first to thirdorganic emission layers 113 a, 113 b, and 113 c respectively emit thesame light, the same organic light emitting material is used, which maybe convenient in terms of a process, e.g., a process for forming adisplay device including the first to third organic emission layers 113a, 113 b, and 113 c. When a third light having higher, e.g., greater,energy than that of a first light or a second light is emitted, quantumdots converting the third light into the first light and/or the secondlight may be used as the quantum dots 16 which will be described later,and the third pixel area PX3 may not need a color filter layer disposedthereon and thus cost saving may be realized and a process for forming adisplay device may be simplified.

In an embodiment, the organic emission layer 113 may be extended, e.g.,extend, to a portion of an upper surface of the pixel define layer 112along the slant structure at the side of the pixel define layer 112,e.g., to a portion of an upper surface of the pixel define layer 112adjacent the slanted side of the pixel define layer 112. Since theorganic emission layer 113 is extended, e.g., extends, to the portion ofthe upper surface of the pixel define layer 112, the color filter layer116 which will be described later may be completely overlapped with aregion where the organic emission layer 113 is formed, e.g., a width ofthe organic emission layer 113 is longer than a width of the colorfilter layer 116, and in addition, when seen from the top of the displaydevice 100, an area of the organic emission layer 113 may be larger thanthat of the color filter layer 116.

The organic emission layer 113 may include a light emitting partincluding the aforementioned organic light emitting material and variousauxiliary layers for respectively supplying, transporting, and blockingelectrons/holes to the light emitting part. The auxiliary layer mayinclude an electron transport layer (“ETL”), a hole transport layer(“HTL”), an electron injection layer (“EIL”), a hole injection layer(“HIL”), an electron blocking layer, a hole blocking layer, or acombination thereof. Each of the auxiliary layers may be formed throughany suitable formation method using any suitable materials.

The second electrode 114 is disposed on the organic emission layer 113.In an embodiment, the second electrode 114 is formed to cover theorganic emission layer 113 and even the upper surface of the pixeldefine layer 112 not covered with the organic emission layer 113 butexposed and thus may be a common electrode.

In an embodiment, the second electrode 114 may serve as alight-transmitting electrode through which light emitted from theorganic emission layer 113 is transmitted. In an embodiment, the secondelectrode 114 may include, for example, silver (Ag), aluminum (Al),copper (Cu), gold (Au), and an alloy thereof, or a metal oxide such asmolybdenum oxide, tungsten oxide, vanadium oxide, rhenium oxide, niobiumoxide, tantalum oxide, titanium oxide, zinc oxide, nickel oxide, copperoxide, cobalt oxide, manganese oxide, chromium oxide, indium oxide, or acombination thereof.

The second electrode 114 may include a semi-permeable materialselectively transmitting a light of a predetermined wavelength region,for example, the third light and for example, a light having awavelength in a range of about 380 nm to about 488 nm.

The light recycle layer 115 may be disposed on the second electrode 114.The light recycle layer 115 may perform a function of transmitting atleast the third light and reflecting the first and second lights havingdifferent wavelengths from the third light. The light recycle layer 115may function as a band-pass filter (“BPF”) selectively transmitting alight having a wavelength in a range corresponding to the third light.For example, the light recycle layer 115 may be a so-called short-wavepass filter (“SWPF”) which selectively transmits a blue light having arelatively short wavelength region and blocks a light having awavelength in a range beyond, e.g., having a wavelength outside thewavelength range for, the blue light, for example, a green light, ayellow light, or a red light.

The light recycle layer 115 is disposed directly on the second electrode114 and directly contacts the second electrode 114 and thus may beformed to cover an entirety of the upper surfaces of the organicemission layer 113 and the second electrode 114.

In an embodiment, the light recycle layer 115 may be formed as oneintegrated layer covering an entirety of the first to third pixel areasPX1, PX2, and PX3 and each non-light emitting area among the pixel areasbut is not necessarily limited thereto. For example, the light recyclelayer 115 may be overlapped with at least the first pixel area PX1 andthe second pixel area PX2 but not formed on the rest of the non-lightemitting area, the third pixel area PX3, or a combination thereof.

Accordingly, while the third light emitted from the organic emissionlayer 113 passes through the light recycle layer 115 and is supplied tothe color filter layer 116, the color filter layer 116 may reflect atleast the first light (the first pixel area) and/or the second light(the second pixel area) and thus emit the first light and/or the secondlight out of the display device 100.

The display device 100 according to an embodiment recycles emits a partof light radiated in all directions from the quantum dots 16 by usingthe light recycle layer 115 and accordingly, may exhibit improvedphoto-efficiency, for example, with respect to the first light and/orthe second light.

The light recycle layer 115 may include a plurality of layers having adifferent refractive index. The light recycle layer 115 may be formedfor example by alternately laminating two layers having a differentrefractive index, for example, by alternately laminating a materialhaving a high refractive index and a material having a low refractiveindex.

The layer having the high refractive index may include for examplehafnium oxide, tantalum oxide, titanium oxide, zirconium oxide,magnesium oxide, cesium oxide, lanthanum oxide, indium oxide, niobiumoxide, aluminum oxide, silicon nitride, or a combination thereof, andmay include various materials having a higher refractive index than thelayer having the low refractive index.

The layer having the low refractive index may include for examplesilicon oxide, and may include a variety of materials having a lowerrefractive index than the layer having the high refractive index.

As a refractive index difference between the layer having a highrefractive index and the layer having a low refractive index isincreased, the light recycle layer 115 having desirable lighttransmittance with respect to the third light and desirable lightreflectance with respect to the first light or the second light may beformed.

In the light recycle layer 115, the thickness and the number layers ofeach of the layer having a high refractive index and the layer having alow refractive index may be determined depending on the refractive indexand a reflection wavelength of each layer, and for example, in the lightrecycle layer 115, each layer having a high refractive index may have athickness of about 3 nm to about 300 nm, and in the light recycle layer115, each layer having a low refractive index may have a thickness ofabout 3 nm to about 300 nm. A total thickness of the light recycle layer115 may be for example in a range of about 0.5 μm to about 5 μm. In thelight recycle layer 115, the thicknesses and materials of each layerhaving a high refractive index and each layer having a low refractiveindex may be the same or different.

In an embodiment, the light recycle layer 115 may have a lighttransmittance for the third light of at least greater than or equal toabout 90%, for example greater than or equal to about 91%, greater thanor equal to about 92%, greater than or equal to about 93%, greater thanor equal to about 94%, greater than or equal to about 95%, greater thanor equal to about 96%, greater than or equal to about 97%, greater thanor equal to about 98%, greater than or equal to about 99%, or about100%.

In addition, the light recycle layer 115 may have a low lighttransmittance for light in the remaining visible light wavelength regionexcept the third light, for example a light transmittance for the firstlight and the second light of less than or equal to about 20%, forexample less than or equal to about 15%, less than or equal to about10%, less than or equal to about 9%, less than or equal to about 8%,less than or equal to about 7%, less than or equal to about 6%, lessthan or equal to about 5%, less than or equal to about 4%, less than orequal to about 3%, less than or equal to about 2%, less than or equal toabout 1%, or about 0%.

The color filter layer 116 is disposed on the light recycle layer 115and includes the quantum dots 16 and thus performs a function ofconverting light supplied from the organic emission layer 113. In anembodiment, the color filter layer 116 may be formed by using acomposition including a binder, a photopolymerizable monomer, aphotoinitiator, and a solvent with the quantum dots 16.

In an embodiment, the color filter layer 116 may be disposed tocorrespond to pixel areas. For example, in an embodiment, the colorfilter layer 116 may be present only on the first pixel area PX1 and thesecond pixel area PX2.

In an embodiment, at least a part of the color filter layer 116 may beaccommodated, e.g., disposed, in the opening 1112. As shown in FIG. 1, alower part of the color filter layer 116 may be accommodated, e.g.,disposed, in the opening 1112.

In an embodiment, the color filter layer 116 includes a first colorfilter layer 116 r including first quantum dots 16 r converting thethird light into the first light and disposed on the first pixel areaPX1 and a second color filter layer 116 g including second quantum dots16 g converting the third light into the second light and disposed onthe second pixel area PX2.

In an embodiment, the color filter layer 116 is formed to be completelyoverlapped with the aforementioned organic emission layer 113, e.g., awidth of the aforementioned organic emission layer 113 is longer than awidth of the color filter layer 116, but a width direction length, e.g.,a width, of the organic emission layer 113 may be longer than that ofthe color filter layer 116. For example, referring to FIG. 1, widthdirection lengths, e.g., widths, W_(L1) and W_(L2) of the first andsecond organic emission layers 113 a and 113 b may be longer than widthdirection lengths, e.g., widths, W_(c1) and W_(c2) of the first andsecond color filter layers 116 r and 116 g.

When the organic emission layer 113 and the color filter layer 116 havethis structural relationship, an area of the organic emission layer 113may be larger than that of the color filter layer 116 with reference toa top view of the display device 100.

Accordingly, the third light emitted from the organic emission layer 113may enter the light recycle layer 115, the color filter layer 116, or acombination thereof at an angle substantially perpendicular to the lightrecycle layer 115, the color filter layer 116, or a combination thereof(i.e., an incident angle of the third light with the light recycle layer115, the color filter layer 116, or a combination thereof is about 0°).Accordingly, the display device 100 may show, e.g., exhibit, improvedphoto-efficiency, for example, with respect to the first light and/orthe second light.

In an embodiment, the width of the organic emission layer 113 may begreater than about 1.00 times or greater than or equal to about 1.01times wider than the width of the color filter layer 116. Within therange, the width of the organic emission layer 113 may be less than orequal to about 1.20 times, less than or equal to about 1.15 times, lessthan or equal to about 1.10 times, less than or equal to about 1.08times, less than or equal to about 1.05 times, less than or equal toabout 1.03 times wider than the width of the color filter layer 116.

For example, referring to FIG. 1, the widths, W_(L1) and W_(L2) of thefirst and second organic emission layers 113 a and 113 b may be greaterthan about 1.00 times or greater than or equal to about 1.01 times widerthan the widths, W_(c1) and W_(c2) of the first and second color filterlayers 116 a and 116 b. Within the range, the widths, W_(L1) and W_(L2)of the first and second organic emission layers 113 a and 113 b may beless than or equal to about 1.20 times, less than or equal to about 1.15times, less than or equal to about 1.10 times, less than or equal toabout 1.08 times, less than or equal to about 1.05 times, less than orequal to about 1.03 times wider than the widths, W_(c1) and W_(c2) ofthe first and second color filter layers 116 a and 116 b.

For example, the widths, W_(L1) and W_(L2) of the first and secondorganic emission layers 113 a and 113 b may be greater than about 1.00times and less than or equal to about 1.20 times, greater than about1.00 times and less than or equal to about 1.15 times, greater thanabout 1.00 times and less than or equal to about 1.10 times, greaterthan about 1.00 times and less than or equal to about 1.08 times,greater than about 1.00 times and less than or equal to about 1.05times, greater than about 1.00 times and less than or equal to about1.03 times wider than the widths, W_(c1) and W_(c2) of the first andsecond color filter layers 116 a and 116 b.

For example, the widths, W_(L1) and W_(L2) of the first and secondorganic emission layers 113 a and 113 b may be greater than or equal toabout 1.01 times and less than or equal to about 1.20 times, greaterthan or equal to about 1.01 times and less than or equal to about 1.15times, greater than or equal to about 1.01 times and less than or equalto about 1.10 times, greater than or equal to about 1.01 times and lessthan or equal to about 1.08 times, greater than or equal to about 1.01times and less than or equal to about 1.05 times, greater than or equalto about 1.01 times and less than or equal to about 1.03 times widerthan the widths, W_(c1) and W_(c2) of the first and second color filterlayers 116 a and 116 b. By having the widths W_(L1) and W_(L2) of thefirst and second organic light emitting layers 113 a and 113 b in therange, the improved effect of the photo-efficiency may be obtainedwithout a loss of the light-emitting area. In an embodiment, the widthof the organic emission layer 113 may be about 80% or more of a totalthickness of the organic emission layer 113, the second electrode 114,and the light recycle layer 115. For example, referring to FIG. 1, thewidths, W_(L1) and W_(L2) of the first and second organic emissionlayers 113 a and 113 b may be about 80% or more of a total thickness ofthe first or second organic emission layers 113 a or 113 b, the secondelectrode 114, and the light recycle layer 115. Within the range, thewidths, W_(L1) and W_(L2) of the first and second organic emissionlayers 113 a and 113 b may be about 80% to 200%, about 80% to 150%,about 80% to 120%, about 86% to 200%, about 86% to 150% or about 86% to120% of a total thickness of the first or second organic emission layers113 a or 113 b, the second electrode 114, and the light recycle layer115. By having the widths W_(L1) and W_(L2) of the first and secondorganic light emitting layers 113 a and 113 b in the range, the thirdlight emitted from the first and second organic light emitting layers113 a and 113 b may enter the light recycle layer 115 and/or the colorfilter layer 116 at an angle substantially perpendicular to the lightrecycle layer 115 and/or the color filter layer 116 without a loss ofthe light-emitting area.

The structural relationship of the organic emission layer 113 with thecolor filter layer 116 and the photo-efficiency improvement effectthereby are described later referring to FIGS. 2 to 4.

The quantum dots 16 included in the color filter layer 116 have adiscontinuous energy bandgap due to a quantum confinement effect andthus may convert incident light through the quantum dots 16 into lighthaving a particular wavelength and radiate it. Accordingly, theconverted light by using the quantum dots 16 may have desirable colorreproducibility and color purity.

In an embodiment, materials of the quantum dots 16 are not particularlylimited and commercially available quantum dots may be used. Forexample, each of the quantum dots 16 according to an embodiment may befor example a Group II-VI compound that does not include Cd, a GroupIII-V compound, a

Group IV-VI compound, a Group IV element or compound, a Group compound,a Group I-II-IV-VI compound that does not include Cd, or a combinationthereof.

The quantum dots 16 according to an embodiment may or may not includecadmium. When the quantum dots 16 are non-cadmium-based quantum dot, thequantum dots 16 have minimal or no toxicity compared with acadmium-based quantum dots and thus are less dangerous and moreenvironmentally-friendly than cadmium-based quantum dots.

The Group II-VI compound may be a binary element compound such as ZnS,ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, or a combination thereof; aternary element compound such as ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe,HgSTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, or a combination thereof; aquaternary element compound such as HgZnTeS, HgZnSeS, HgZnSeTe, HgZnSTe,or a combination thereof; or a combination thereof. The Group II-VIcompound may further include a Group III metal.

The Group III-V compound may be a binary element compound such as GaN,GaP, GaAs, GaSb, AlN, AIP, AIAs, AlSb, InN, InP, InAs, InSb, or acombination thereof; a ternary element compound such as GaNP, GaNAs,GaNSb, GaPAs, GaPSb, AINP, AINAs, AINSb, AIPAs, AIPSb, InNP, InNAs,InNSb, InPAs, InPSb, InZnP, or a combination thereof; a quaternaryelement compound such as GaAINP, GaAINAs, GaAINSb, GaAIPAs, GaAIPSb,GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAINP, InAINAs, InAINSb,InAIPAs, InAIPSb, or a combination thereof; or a combination thereof.The Group III-V compound may further include a Group II metal (InZnP).

The Group IV-VI compound may be a binary element compound such as SnS,SnSe, SnTe, PbS, PbSe, PbTe, or a combination thereof; a ternary elementcompound such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS,SnPbSe, SnPbTe, or a combination thereof; a quaternary element compoundsuch as SnPbSSe, SnPbSeTe, SnPbSTe, or a combination thereof; or acombination thereof. Examples of the Group compound may be CuInSe₂,CuInS₂, CuInGaSe, and CuInGaS, are not limited thereto. Examples of theGroup I-II-IV-VI compound may be CuZnSnSe and CuZnSnS, are not limitedthereto. Examples of the Group IV compound may be a single substancesuch as Si, Ge, or a combination thereof; a binary element compound suchas SiC, SiGe, or a combination thereof; or a combination. The binaryelement compound, the ternary element compound, or the quaternaryelement compound respectively exists in a uniform concentration in theparticle or in partially different concentrations, e.g., concentrationgradients, in the same particle.

According to an embodiment, the quantum dots 16 may have a core-shellstructure including one semiconductor nanocrystal core and anothersemiconductor nanocrystal shell surrounding the core. The core and theshell may have a concentration gradient wherein the concentration of theelement(s) of the shell decreases in a direction from the shell towardthe core. In addition, the quantum dots 16 may have a structureincluding one semiconductor nanocrystal core and multi-shellssurrounding the core. Herein, the multi-layered shell structure has astructure of two or more shells and each layer may have a singlecomposition or an alloy or may have a concentration gradient.

When the quantum dots 16 have a core-shell structure, a materialcomposition of the shell may have larger, e.g., higher, bandgap energythan that of the core, which may exhibit an effective quantumconfinement effect. In the multi-layered shell, a shell that is outsideof the core may have a higher, e.g., larger, bandgap energy than a shellthat is near, e.g., closer, to the core and quantum dots may emit lighthaving a wavelength in ultraviolet (“UV”) to infrared ranges.

The quantum dots 16 may have quantum efficiency of greater than or equalto about 10%, for example, greater than or equal to about 20%, greaterthan or equal to about 30%, greater than or equal to about 40%, greaterthan or equal to about 50%, greater than or equal to about 60%, greaterthan or equal to about 70%, greater than or equal to about 80%, greaterthan or equal to about 90%, or 100%.

In addition, in the display device 100, the quantum dots 16 may have arelatively narrow spectrum so as to improve color purity or colorreproducibility. The quantum dots 16 may have for example a full widthat half maximum (“FWHM”) of a photoluminescence wavelength spectrum ofless than or equal to about 45 nm, less than or equal to about 40 nm, orless than or equal to or about 30 nm, and greater than or equal to about1 nm, greater than or equal to about 2 nm, or greater than or equal toor about 3 nm. Within the ranges, color purity or color reproducibilityof a display device 100 may be improved.

The quantum dots 16 may have a particle diameter (the longest diameterfor a non-spherically shaped particle) of about 1 nm to about 100 nm.For example, the quantum dots 16 may have a particle diameter of about 1nm to about 20 nm, for example, about 2 nm (or about 3 nm) to about 15nm.

In addition, the shapes of the quantum dots 16 may not be particularlylimited. For example, the quantum dots 16 may have a spherical shape, anoval shape, a tetrahedral shape, a pyramidal shape, a cuboctahedralshape, a cylindrical shape, a polyhedral shape, a multi-armed shape, ormay be in the shape of cubic nanoparticle, a nanotube, a nanowire, ananofiber, a nanosheet, or a combination thereof. The quantum dots 16may have any suitable cross-sectional shape.

The quantum dots 16 may be commercially available or may be synthesizedin any suitable method. For example, several nano-sized quantum dots 16may be synthesized according to a wet chemical process. In the wetchemical process, precursor materials react in an organic solvent togrow crystal particles. Herein, organic solvents or ligand-formingmaterials are naturally coordinated with, e.g., bound to, the surface ofthe quantum dots 16 to control a crystal growth.

An amount of the organic material coordinated on, e.g., to, the surfaceof the quantum dots 16 may be less than or equal to about 50 weightpercent (wt %), for example, less than or equal to about 30 wt %, lessthan or equal to about 20 wt %, or less than or equal to about 10 wt %,based on a total weight of the quantum dots, and greater than or equalto about 0.001 wt %, for example, greater than or equal to about 0.01 wt%, or greater than or equal to about 0.1 wt %, based on a total weightof the quantum dots. This organic material may include a ligand boundon, e.g., to, the surface of the quantum dots 16, a residual organicsolvent, or a combination thereof.

In an embodiment, the color filter layer 116 may include a predeterminedamount of the quantum dots 16 to show excellent, e.g., exhibitdesirable, luminous efficiency.

For example, the quantum dots 16 may be included for example in anamount of greater than or equal to about 5 wt %, greater than or equalto about 10 wt %, greater than or equal to about 15 wt %, or greaterthan or equal to about 20 wt %, and for example less than or equal toabout 98 wt %, less than or equal to about 95 wt %, less than or equalto about 90 wt %, less than or equal to about 85 wt %, less than orequal to about 80 wt %, less than or equal to about 75 wt %, less thanor equal to about 70 wt %, less than or equal to about 65 wt %, lessthan or equal to about 60 wt %, less than or equal to about 55 wt %, orless than or equal to about 50 wt %, or for example in a range of about5 wt % to about 98 wt %, about 20 wt % to about 98 wt %, about 20 wt %to about 90 wt %, about 20 wt % to about 85 wt %, or about 50 wt % toabout 85 wt %, based on a total weight of the color filter layer 116.

The specific amount of the quantum dots 16 may be changed depending on,for example, a material of the used quantum dots 16, a type of emittedlight, or a material or a thickness of the light recycle layer 115.

The first and second color filter layers 116 r and 116 g according to anembodiment respectively may further include a light scatterer in orderto improve emission efficiency of the first or second lights andfront/side luminance uniformity. The light scatterer may include anysuitable material evenly scattering light without a particular limit,for example, silica (SiO₂), hollow silica (SiO₂ having a hollowstructure), TiO₂, ZrO₂, Al₂O₃, In₂O₃, ZnO, SnO₂, Sb₂O₃, ITO, or acombination thereof.

In an embodiment, the display device 100 may further include atransmissive layer 117 neighboring, e.g., adjacent to, the first colorfilter layer 116 r, the second color filter layer 116 g, or acombination thereof in a parallel direction to the upper surface of thesubstrate 110. Stated otherwise, the display device 100 may furtherinclude a substrate 110, the first electrode may be disposed on an uppersurface of the substrate 110, and the display device 100 may furtherinclude a transmissive layer 117 adjacent to the first color filterlayer 116 r, the second color filter layer 116 g, or a combinationthereof in a direction parallel to the upper surface of the substrate.The transmissive layer 117 may fill the third pixel area PX3. Thetransmissive layer 117 may be formed of a transparent polymer andtransmit the third light emitted from the third organic emission layer113 c, so that the third pixel area PX3 may emit the third light.

The transmissive layer 117 includes a material capable of transmittingthe incident third light without a particular phosphor, quantum dot, ora combination thereof. For example, the transmissive layer 117 mayinclude a polymer including, for example, a photosensitive resin.

The transmissive layer 117 according to an embodiment may furtherinclude a light scatterer to improve emission efficiency of the thirdlight and front/side luminance uniformity. Examples of the light scattermay be the same as included in the aforementioned first and second colorfilter layers 116 r and 116 g and thus will not be described in detail.

The display device 100 according to an embodiment may further include alight blocking member 118 disposed in each gap among the first colorfilter layer 116 r, the second color filter layer 116 g, and thetransmissive layer 117. The light blocking member 118 may be formed of amaterial not transmitting light, for example, metal particles such as,for example, chromium (Cr), silver (Ag), molybdenum (Mo), nickel (Ni),titanium (Ti), or tantalum (Ta), oxides of the metal particles, or acombination thereof. The light blocking member 118 may minimize orprevent color mixing, light leakage, or a combination thereof in thedisplay device 100 and thus improve a contrast of the display device100.

Hereinafter, referring to FIGS. 2 to 4, the structural relationship ofthe organic emission layer 113 with the color filter layer 116 accordingto an embodiment and a photo-efficiency improvement effect thereby aredescribed.

FIG. 2 is a schematic diagram schematically illustrating a lightconversion process of a color filter layer in one pixel of a displaydevice according to an embodiment, FIG. 3 is a schematic diagramschematically illustrating a light conversion process of a color filterlayer when characteristics of the display device according to anembodiment are not satisfied, and FIG. 4 is a graph showing lighttransmittance changes of the light recycle layer depending on awavelength according to viewing angle changes.

FIGS. 2 and 3 show the first pixel area PX1 as an example, which isadopted for convenient explanation, but the structural relationship andthe effect thereby which will be described later may be equally appliedto the second pixel area PX2.

FIG. 4 shows light transmittance depending on a wavelength of a lightrecycle layer at each viewing angle of 0°, 15°, 30°, 45°, and 60° withreference to a viewing angle of an incident light into the light recyclelayer.

First, referring to FIG. 2, in the display device 100 according to anembodiment, blue lights (B of FIG. 2) emitted from the first organicemission layer 113 a may pass the second electrode 114 and sequentially,enter the light recycle layer 115 and the first color filter layer 116r.

The incident lights enter the first quantum dots 16 r, and the firstquantum dots 16 r convert the blue lights (B) into red lights and thusradiate the red lights into all directions. Herein, the red lightsradiated into all light-emitting directions of the display device 100are emitted out of the display device 100 (R of FIG. 2), and herein, thered lights radiated into a direction of the light recycle layer 115 arereflected (recycled) on the interface of the light recycle layer 115 andthen, emitted out of the display device 100 (R′ of FIG. 2).

In addition, referring to FIG. 2, the blue lights (B) respectivelyentering the light recycle layer 115 and the first color filter layer116 r may enter at an angle substantially perpendicular to the lightrecycle layer 115 and the first color filter layer 116 r (at an incidentangle of about 0°).

In the display device according to an embodiment, the blue lights (B)may enter the light recycle layer 115 and the first color filter layer116 r at an angle substantially perpendicular to the interfaces of thelight recycle layer 115 and the first color filter layer 116 r in thefirst pixel area PX1.

FIG. 3 shows that unlike the display device 100 according to anembodiment, a first color filter layer 6 is not completely overlappedwith a first organic emission layer 3 but is extended to be longer,e.g., extends farther, than a first organic emission layer 3.

Herein, a blue light (B of FIG. 3) emitted from the end of the firstorganic emission layer 3 toward the end of the first color filter layer6 not overlapped with the first organic emission layer 3 enters a secondelectrode 4, a light recycle layer 5, and the first color filter layer 6respectively at an angle of a ° (0 <α<90°). The incident angle may bevariable depending on a width of an area where the end of the firstorganic emission layer 3 is not overlapped with the light recycle layer5.

Referring to FIG. 4, light transmittance of the light recycle layer maychange depending on an incident angle, and for example, lighttransmittance about, e.g., of, light of a short wavelength such as, forexample, blue light may change.

For example, when the incident angle is about 0°, as shown in FIG. 2,the light recycle layer 115 may exhibit light transmittance of greaterthan or equal to about 90%, for example greater than or equal to about90%, greater than or equal to about 91%, greater than or equal to about92%, greater than or equal to about 93%, greater than or equal to about94%, greater than or equal to about 95%, greater than or equal to about96%, greater than or equal to about 97%, greater than or equal to about98%, greater than or equal to about 99%, or about 100% over the entireblue light wavelength region, as shown in FIG. 4. Accordingly, thedisplay device according to an embodiment has a structure shown in FIG.2 and may function as an excellent blue light transmittance filter.

As shown in FIG. 3, in a display device having an incident angle of α°,as the α° gradually increases to 15°, 30°, 45°, and 60°, a lighttransmittance curve of the light recycle layer 5 is gradually shiftedtoward the left, and the display device may exhibit non-uniform lighttransmittance in a blue light wavelength region and deteriorated lighttransmittance in some wavelength regions.

In addition, as the incident angle gradually increases, lighttransmittance of the light recycle layer about, e.g., of, a longwavelength region such as green and red light wavelength regionsunintentionally increases. While not wanting to be bound by theory, itis understood that the increase is caused by the left shift of the lighttransmittance curve according to, e.g., with, the incident angleincrease.

Accordingly, as an incident angle of a third light entering the lightrecycle layer 5 gradually increases, blue light transmittance may notonly be gradually deteriorated, but also light transmittance about,e.g., of, light having a longer long wavelength than that of the bluelight may unintentionally increase. Accordingly, when the incident angleinto the light recycle layer is not adjusted into an appropriate level,the light recycle layer may not only not perform a desired function butalso deteriorate light efficiency of the display device.

Accordingly, when an area of the organic emission layer 113 per eachpixel is formed to be larger than that of the color filter layer 116, asshown in the display device 100 according to an embodiment, blue lightsmay enter the light recycle layer 115 and the color filter layer 116 atan angle substantially perpendicular to all the interfaces of the lightrecycle layer 115 and the color filter layer 116 in each pixel area.Accordingly, photo-efficiency, for example, in the first pixel area PX1and the second pixel area PX2 where the color filter layer 116 isdisposed may be improved.

Hereinafter, referring to FIGS. 5 to 9, various exemplary variations ofthe display device according to an embodiment are illustrated.

FIGS. 5 to 8 are cross-sectional views showing various exemplaryvariations applying, e.g., including, a concavo-convex, e.g.,undulating, structure to the second electrode the light recycle layer,or a combination thereof of the display device according to anembodiment.

Referring to FIGS. 5 to 8, the second electrodes, light recycle layers,or a combination thereof according to exemplary variations may have aconcavo-convex, e.g., undulating, structure.

For example, as shown in FIG. 5, the entire upper surface of a secondelectrode 114′ may have a concavo-convex, e.g., undulating, structure,and as shown in FIG. 6, the entire upper surface of a light recyclelayer 115″ may have a concavo-convex, e.g., undulating, structure, andas shown in FIG. 7, the entire upper surface of a second electrode 114″and the entire upper/lower surfaces of a light recycle layer 115′″ mayhave a concavo-convex, e.g., undulating, structure.

The concavo-convex, e.g., undulating, structure may not be formed allover, e.g., on an entirety of, the second electrodes, light recyclelayers, or a combination thereof. For example, as shown in FIG. 8, theupper surface of a second electrode 114′″ overlapped with the uppersurface of a pixel define layer and a part of the lower surface of alight recycle layer 115′″ may have a concavo-convex, e.g., undulating,structure.

In this way, when the concavo-convex, e.g., undulating, structure isapplied to the surfaces of the second electrodes, the light recyclelayers, or a combination thereof, a perpendicular incident ratio of thethird light to the light recycle layers and the color filter layers maybe further improved, and photo-efficiency of a display device may befurther improved.

FIG. 9 is a cross-sectional view showing a display device furtherincluding a third light blocking layer according to an exemplaryvariation. Referring to FIG. 9, the display device 100′ according to anexemplary variation may further include a third light blocking layer 119disposed on the color filter layer 116 and overlapped with the firstcolor filter layer 116 r, the second color filter layer 116 g, or acombination thereof.

The third light blocking layer 119 may be formed of a materialtransmitting the first and second lights having a relatively longerwavelength and reflecting or absorbing the third light having arelatively shorter wavelength. The third light blocking layer 119 may bea long-wavelength pass filter (“LWPF”) and thus perform an oppositefunction to the aforementioned light recycle layer 115.

Like the aforementioned light recycle layer 115, the third lightblocking layer 119 also may include a plurality of layers having adifferent refractive index. The third light blocking layer 119 may beformed for example by alternately laminating two layers having adifferent refractive index, for example, alternately laminating amaterial having a high refractive index and another material having alow refractive index.

The material having a high refractive index, the material having a lowrefractive index, and each a thickness of each of the materials may bethe same as those of the aforementioned light recycle layer 115, and thethird light blocking layer 119 may be formed to function as theaforementioned long wavelength pass filter.

In an embodiment, the third light blocking layer 119 may be extended,e.g., may extend, as one integrated layer from the first pixel area PX1to the second pixel area PX2. The disposition of the third lightblocking layer 119 may be variously modified under a condition of atleast covering the first color filter layer 116 r and the second colorfilter layer 116 g.

In this way, when two optical filters of the light recycle layer 115 andthe third light blocking layer 119 are used to control lights emittedfrom the first and second pixel areas PX1 and PX2, the display device100′ may have excellent photo-efficiency, e.g., exhibit desirablephoto-efficiency, and emit light having high color purity.

While this disclosure has been described in connection with what ispresently considered to be practical example embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments. On the contrary, it is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A display device comprising a first electrode, apixel define layer disposed on the first electrode, the pixel definelayer comprising an opening, an organic emission layer disposed on thepixel define layer, the organic emission layer in electricalcommunication with the first electrode through the opening, a secondelectrode disposed on the organic emission layer, a light recycle layerdisposed on the second electrode, and a color filter layer disposed onthe light recycle layer, the color filter layer comprising a quantumdot, wherein a width of the organic emission layer is longer than awidth of the color filter layer.
 2. The display device of claim 1,wherein a side of the pixel define layer adjacent the opening is slantedwith respect to an upper surface of the pixel define layer, and theorganic emission layer extends from the first electrode to a portion ofthe upper surface of the pixel define layer adjacent the slanted side ofthe pixel define layer.
 3. The display device of claim 1, wherein awidth of the opening is longer than or equal to the width of the colorfilter layer.
 4. The display device of claim 3, wherein at least oneportion of the color filter layer is disposed in the opening.
 5. Thedisplay device of claim 1, wherein the organic emission layer emits athird light, and the light recycle layer transmits the third light andreflects a first light and a second light, each of which has a differentwavelength than the third light.
 6. The display device of claim 5,wherein the first light is red light, the second light is green light,and the third light is blue light.
 7. The display device of claim 5,wherein the light recycle layer has a transmittance for the third lightof about 90% to about 100%.
 8. The display device of claim 5, whereinthe light recycle layer has a transmittance for each of the first lightand the second light of about 0% to about 20%.
 9. The display device ofclaim 5, wherein the light recycle layer has a thickness of about 0.5micrometers to about 5 micrometers.
 10. The display device of claim 5,wherein the color filter layer comprises a first color filter layercomprising a first quantum dot configured to convert the third lightinto the first light, and a second color filter layer comprising asecond quantum dot configured to convert the third light into the secondlight.
 11. The display device of claim 10, further comprising asubstrate, the first electrode being disposed on an upper surface of thesubstrate; and a transmissive layer adjacent to the first color filterlayer, the second color filter layer, or a combination thereof in adirection parallel to the upper surface of the substrate.
 12. Thedisplay device of claim 11, wherein the transmissive layer comprises alight scatterer.
 13. The display device of claim 11, further comprisinga light blocking member between each of the first color filter layer,the second color filter layer, and the transmissive layer in thedirection parallel to the upper surface of the substrate.
 14. Thedisplay device of claim 10, wherein the light recycle layer isoverlapped with the first color filter layer, the second color filterlayer, or a combination thereof.
 15. The display device of claim 10,wherein the second electrode and the light recycle layer are in directcontact with each other, and at least one portion of an upper surface ofthe second electrode comprises an undulating structure.
 16. The displaydevice of claim 10, wherein the second electrode and the light recyclelayer are in direct contact with each other, at least one portion of anupper surface of the light recycle layer comprises an undulatingstructure, and at least one portion of a lower surface of the lightrecycle layer comprises an undulating structure.
 17. The display deviceof claim 10, further comprising a third light blocking layer disposed onthe color filter layer and overlapped with the first color filter layer,the second color filter layer, or a combination thereof.
 18. The displaydevice of claim 1, wherein the quantum dot comprises a Group II-VIcompound that does not comprise Cd, a Group III-V compound, a GroupIV-VI compound, a Group IV element or compound, a Group I-III-VIcompound, a Group I-II-IV-VI compound that does not comprise Cd, or acombination thereof.
 19. The display device of claim 1, wherein thequantum dot has a core-shell structure.